Perennial Sweet Pea The perennial sweet pea is useful as a bank cover, cascading over a wall or trained on wire fence. It has gray-green foliage that grows up to 6 ft. in length. Pink flowers are produced during July-August if it receives monthly feeding during blooming. Grow in full sun to light shade, well-drained soil and water 1-2 times per week. This plant is not bothered by rabbits, squirrels nor deer. (Plant 4 ft. on center).